1. Field of the Invention
The present invention relates to a vibration isolating apparatus which has an inner tube and an outer tube and which may be employed as an engine mount of the like.
2. Description of the Related Art
Vibration isolating apparatuses include a so-called bush type rubber vibration isolator in which an inner tube and an outer tube are disposed coaxially or axially parallel with each other, and one type of such vibration isolating apparatus wherein a liquid chamber is provided in a resilient member disposed between the inner and outer tubes has already been proposed (see Japanese Patent Laid-Open No. 179542/1985).
In such conventional vibration isolating apparatus, the liquid chamber is partitioned into a plurality of small liquid chambers, and these chambers are communicated with each other through an orifice. If the dimensions of this orifice are set so as to damp low-frequency vibrations of relatively large amplitude, when a high-frequency vibration of relatively small amplitude occurs, the dynamic scale factor is increased and this causes the vibration transmitting characteristics to be undesirably deteriorated. Conversely, if the dimensions of the orifice are set so as to improve the vibration transmitting characteristics for high-frequency vibrations of relatively small amplitudes, it is impossible to damp low-frequency vibrations of relatively large amplitude, disadvantageously.